IGAB, if you are keen on a Slammer III - say the 5500 size (20kg drag, 97cm retrieve, and 300m of 40lb braid capacity), you could get one landed in NZ from anglerswarehouse in Aussie for NZ$280, saving yourself about $70 to spend on jigs compared to the NZ shop prices i can see online.
The 4500 that MB has is the same price in Australia, about 200g lighter and designed for PE2 or similar line. I have one that I use with 20lb braid for my heaviest soft bait set up, casting 1oz jigheads etc. Really nice reel for the price. Guess it depends on the PE rating you're aiming for.
RokkitKit, who is a prominent YouTube kayak guy out of the Gold Coast, uses Penn Slammer IIIs and really rates them for their robustness in very wet situations. He opened up his 3-yr-old Slammer in one vid and was amazed to see how good it was inside after nil servicing and a hard life bashing out through surf.
Marine Deals has the Daiwa BG 5000 for about $250, but that's got a retrieval of 120cm per turn, which may be a bit fast for spin mechanical jig?? Claims max drag of 10kg.
The BG doesn't have Daiwa's mag seal, so easier and cheaper to service, but supposedly not as sealed as the Slammer or other Daiwa reels.
Both of those reels are a bit over 600g, so about double the weight of a typical soft bait reel.
The Shimano Saragosa 6000 might be another option, though appears to be about $50 above your budget. Similar specs to the other reels above (103cm retrieve, 600g weight, 10kg drag).